Wire Rope Fatigue Life Calculation

As a first step an improved grey prediction model is established to predict the reliability life data of wire rope under small sample condition.

Wire rope fatigue life calculation.

In this paper the fatigue life prediction method of wire rope based on grey theory will be used to predict the fatigue life of wire rope under the condition of small sample whole rope test data. Ratio b 22 5 sheave diameter 3 4 wire rope diameter 30 ratio b 12 sheave diameter 3 4 wire rope diameter 16. Of wire rope bending fatigue tests. Calculation and to demonstrate the potential and limitations of the forecasting procedure.

But it is essentially a collection of small filaments wound around each other in a manner that largely retains its shape when bent crushed and or tensioned. As these are accepted as a fixed percentage it is ignored in the counting. The feyrer formula reads lg n b. As the fatigue cycle counter described is based around empirical setting of limits the fixed values of d d ratio means it is ignored in this.

They examined the effect of essential factors of influence on the service life of the rope. Subsequently the fatigue life of wire rope is calculated by using the linear cumulative damage theory of fatigue. Feyrer from the university of stuttgart has summed up their findings in a formula which allows to predict the service life of wire ropes in reeving systems with sufficient accuracy. If the same rope works over a sheave with a d d ratio of 55 1 271 2 sheave its service life increases to 76 5 units.

Part three empirical assessment of steel wire rope service life using bending fatigue calculation. Wire rope is also known by many other names such as. Wire multi strand wire flexible wire cable cord steelcord etc. The wire rope fatigue test rig is established and the experimental value of the fatigue life of wire rope is compared with the theoretical calculation value.

To determine the extension of fatigue life for a 3 4 wire rope using a 22 5 diameter sheave versus a 12 diameter sheave. The individual wires in wire rope have a fatigue life limit which when exceeded will cause them to break. Calculating the number of sustainable bending cycles even the inventor of the wire rope oberbergrat albert from clausthal zellerfeld carried out fatigue tests with wire ropes to compare the service lives of different rope designs. Feyrer from the university of stuttgart has summed up their findingsin a formula which allows to predict the service life of wire ropes in reeving systems with sufficient accuracy.

They examined the effectof the essential factors of influenceon the service life of the rope. Typical external fatigue breaks are visible on the outside of the wire rope where the crown of the strand is in contact with the sheaves drums and other contact points on the crane.